The mammalian cell expression system is by far the most used production platform for glycoproteins production. Production of glycoproteins is currently achieved by either transient or stable gene expression in the cells. Although the level of protein obtained by transient expression is not as high as with stable gene expression, it is still sufficient for many applications. When it comes to the production of glycoproteins in large quantities, stable gene expression systems remain the preferred avenue.
With years of research and experience in mammalian cell glycoengineering, multiple adverse factors have been tackled and optimized for improving the productivity of glycoprotein, process robustness, and reducing cell line generation timelines. Creative Biolabs has successfully developed our own glyco-engineered Chinese hamster ovary (CHO) cells and glyco-engineered human embryonic kidney 293 (HEK293) cells for glycoprotein production. We can offer high-quality customized services by adjusting strategies to meet even the most specific requirements in the production of glycoprotein.
A significant portion of biopharmaceutical products are recombinant proteins, with an ongoing increase in the number of them produced in mammalian expression platforms. This trend is mostly driven by the increased attention directed to post-translational modifications (PTM) of these biologics, in particular towards their glycosylation state. Scientists have made great efforts to understand how glycosylation can influence the biological activity of therapeutics. Studies have shown that proper glycosylation can improve protein properties, such as high stability, the long half-life, and low immunogenicity, etc.
Among the mammalian systems, CHO cell is by far, the most commonly used cell line. It is involved in the production of over 70% of recombinant biopharmaceutical proteins. CHO system is widely used for glycoprotein production due to numerous advantages. 1) Different gene expression systems have been developed and used in CHO cells, which allow for high titer yields and good specific productivity. 2) CHO cells can achieve a substantial production rate and can be adapted to grow in various serum-free and chemically defined culture media. Thus, this system is suitable for large-scale industrial suspension culture. 3) CHO system can produce glycoproteins with human-like glycans, making the generated products more likely to be compatible and bioactive within human hosts. 3) Moreover, CHO cell is refractory to infection by human viruses, which minimizes biosafety risks. Many biotherapeutic glycoproteins approved, such as Siltuximab (SYLVANT®), Pertuzumab (PERJETA®) and Rituximab (RITUXAN®), tissue plasminogen activator (tPa, ACTILYSE®, ACTIVASE®) and human DNAse (PULMOZYME®) are generated in CHO cells.
One way to favor human-like glycosylation would be to use human cell lines for recombinant protein production. This strategy would warrant that proteins harbor, if not the ideal glycosylation pattern, at least a non-immunogenic glycans. HEK293 is the most commonly used human cell lines to manufacture glycoprotein therapeutics are the HEK293 cells. Drotrecogin alfa (Xigris®), the first therapeutic glycoprotein produced in HEK293 approved by FDA and EMA, was accepted by both agencies in 2001 and 2002 respectively. However, it was removed from the market in 2011, since it failed to show significant beneficial effects.
Fig.1 Diagrammatic representation of the major classes of N-linked sugars produced by mammalian cells. (Nettleship, 2012)
Creative Biolabs has engineered CHO system and HEK 293 system for glycoprotein production. Those systems can even ensure the natural folding and sugar chain composition of glycoprotein, and significantly increase the expression level of glycoprotein, and fundamentally solve the problem of humanization of recombinant glycoprotein.
The signal peptide in the vector is an artificial signal peptide with the strongest secretion ability derived by bioinformatics, which greatly promotes the production of secreted proteins. Genetic element has been added in upstream of the promoter and downstream of the poly A to protect the target gene and shield gene silencing, which is a major limiting factor in obtaining highly expressing cell lines.
In addition to a mature and efficient expression vector, we use gene-editing technology to insert glycosylated elements or knock out glycosylated genes to modify the host CHO cells and HEK 293 cells to improve the glycosylation of the target protein.
Our technical team has rich experience in CHO cell and HEK 293 cell expression systems. We are dedicated to serving as your one-stop-shop for glycoprotein production, from codon optimization, selecting the appropriate signal peptide, choosing the appropriate transfection and screening methods, improving the success rate and yield of glycoprotein expression, etc.
Creative Biolabs is a leading service provider that focuses on developing glycoproteins and glycosylated monoclonal antibodies with high-specificity and high-affinity for research, diagnostic, and therapeutic use. We own qualified mammalian cell lines for the development of glycoprotein. If you are interested in glycoprotein production, please contact us for more information and a detailed quote.